SmugMug provides you with several site-level and gallery-level settings that help you manage comments on your galleries and photos.
Allow comments.
You can allow your visitors to leave comments on your photos. Find the option in your Gallery Settings under Social > Allow Comments.
Gallery comments.
This is a separate content block that can be added to any page, gallery, or folder. You can find it in the Customize Design menu under Content > Social > Comments. Drag and drop the box onto the page where you want it to appear.
Content blocks can be positioned anywhere on your page. You can control the size and position as you wish.
This content block is NOT controlled by the gallery settings linked above.
Adding this content block to a page automatically turns comments on. You'll be able to choose the source gallery the comments are pulled from.
Moderate comments.
Approve or delete comments before they're made public on your site. Enable this feature in your Account Settings under Stats > Comments > Details.
Receive notifications.
Receive an email notifying you when a visitor leaves a comment. Find it in your Account Settings > Me > Notifications tab. Look for the Comment Alerts header and toggle it to ON.
Who can comment.
To protect your site from spammers, visitors are required to log in to leave comments. They can use either a SmugMug account or Google to log in and leave a comment. A log-in is required and it's not possible to turn off that requirement.
Your commenters can also use the star-rating area to rate your photos if they choose. Once they've logged in using one of the above methods, they'll see five stars outlined below the comment box. They can click a single star or all five stars to show how much they love your photo!